Some disreputable car dealers install junkyard packs as-is. I suggest not succumbing to the temptation of simply replacing a malfunctioning pack with an untested junkyard one. Even though the junkyard pack I bought was only one year old when its car was wrecked and had sat on a warehouse shelf since 2005, it still had two malfunctioning sticks. Spend the time, and do the testing diligently!